Crimping tool



March 3, 1959 w. J. WYN NE, JR

CRIMPING TOOL Filed Oct. 10, 1957 FIG. 3.

INVENTOR. WILLIAM J. WYNNE,JR.

' his ATTORNEYS.

United States Patent-O CRIMPING TOOL William Joseph Wynne, In, New York, N. Y. Application October 10, 1957, Serial No. 689,324

3 Claims. (CI. 81-45) The present invention, generally, relates to a new and useful improvement in hand tools for crimping sheet metal and, more particularly, to an improvement in a tool for crimping corners of sheet metal ducts.

A principal object of the invention is to provide a tool for crimping the corners of angular shaped ducts or conduits in order to reduce the size of the ends and enable matching sections to be telescoped.

A further object of the invention is to provide a tool that is simple and inexpensive to produce, which tool will enable a worker to crimp more efficiently the corners of sheet metal ducts.

Generally, the invention provides a tool with two working surfaces disposed at an included angle which is substantially equal to the angle of a corner of a duct to be crimped. An anvil is positioned symmetrically on the tool at a point opposite the included angle of the working surfaces and in a plane that bisects the included angle for receiving a blow from a suitable instrument. The tool is held in position by means of a lever or handle which is fomed by extending the two working surfaces.

A representative embodiment of the invention from which the above and other features and objects thereof will be readily understood is described below, having reference to the accompanying drawing in which:

Figure 1 is a perspective view illustrating the preferred embodiment of the invention;

Figure 2 is a side elevation of the working end of the tool shown in Figure 1;

Figure 3 is a plan view of Figure 2; and

Figure 4 is a perspective view showing the positioning of the tool of Figure 1 in operation.

Referring now to an illustrative embodiment of the invention as shown in Figure 1 of the drawing, the reference numeral refers generally to the crimping tool which is formed of any suitable hard material such as iron or steel. This view of the crimping tool 10 shows one relative position of working surfaces 11 and 12 for crimping a corner of a rectangular duct. These working surfaces 11 and 12 are disposed at an included angle of approximately 90 with respect to each other and are attached along one elongated edge 13 to form this included angle. To position the tool relative to a corner to be crimped, the working surfaces are extended to form a positioning lever or handle 14 formed of any suitable substance, such as for example, plastic, wood or the like. The positioning lever or handle 14 shown in Figure 1 is merely illustrative, it being understood that this lever 14 may be of any desired configuration.

A fillet 23 is formed within the included angle between the surfaces 11 and 12 to crimp the corner of a duct. This fillet 23 has a preferred radius of & inch, although radii in the approximate range of have been found to operate satisfactorily. The construction of the fillet 23 may be by any suitable means such as by cementing a preformed block to the surfaces 11 and 12 or by filling the enclosed angle between the surfaces 11 and 12 with weld material.

As shown particularly in Figures 2 and 3 of the drawing, an anvil 15 is positioned on the tool at the working end opposite from the handle 14 and at a point on the tool opposite the angle included by the working surfaces 11 and 12. The anvil 15 is attached to the tool 10 by any suitable means, as for example, by weld 16. The outer end of the anvil 15 is formed at a convenient angle to provide an anvil surface 17 to receive a blow from an instrument, as for example, a hammer. It is important that when attaching the anvil 15 to the tool 10 it be positioned in a plane which substantially bisects the included angle between the working surfaces 11 and 12 as best shown in Figure 3. This is to insure that a blow applied to the anvil surface 17 is distributed uniformly to a corner to be crimped.

In use, the tool 10 is positioned over a corner of a duct 18, Figure 4, by holding the tool with the handle 14 at a convenient angle. The anvil surface 17 is then struck by an instrument such as a hammer to crimp the corner. As the force of the ahmmer is transmitted to the corner to be crimped by the fillet 23, the portions 19 and 20 of the edges 21 and 22, respectively, are indented in a concave fashion as illustrated in Figure 4. After each of the corners of the duct 18 have been thus crimped, it may be fitted within another matching duct to form a relatively tight junction.

It may be seen that without the working surfaces 11 and 12 to guide the portions of the duct adjacent the corner, the application of a force to a corner of the duct 18 would, generally, cause the portions 19 and 20 to bow outwardly in a convex fashion, thus preventing the insertion of this duct within a matching duct. Therefore, it is conceivable that the working surfaces 11 and 12 could be formed, instead of as fiat surfaces, to present a slightly convex curved surface to act against the portions 19 and 20. However, in the preferred embodiment, it is found that it is less expensive, and also easier to manufacture, to provide the surfaces 11 and 12 as simply elongated flat surfaces.

Obviously, many modifications and variations of the present invention are possible in the light of the above teachings. Therefore, it is to be understood that the invention is not limited in its applications to the details of construction and arrangement of parts specifically described or illustrated and that within the scope of the appended claims, it may be practiced otherwise than as specifically described or illustrated. It is, therefore, understood that certain details of arrangement and proportions of parts may be variously modified without exceeding the scope of the appended claims.

I claim:

1. A crimping tool for preparing the corners of a rectangular duct to fit into a matching duct, which tool comprises a first substantially rectangular working surface and a second substantially rectangular working surface, said working surfaces being attached along one edge to include a substantially angle, an anvil surface positioned symmetrically on said tool adjacent one end at a point opposite the included 90 angle to receive a blow for crimping a corner of a duct, and a positioning lever at the opposite end of said tool from said anvil to position the tool relative to a corner to be crimped.

2. A crimping tool for preparing the corners of a rectangular duct to fit into a matching duct, which tool comprises an elongated first substantially rectangular working surface and an elongated second substantially rectangular working surface, said first and said second working surfaces being attached along one elongated edge to include a substantially 90 angle, a raised portion positioned on said tool adjacent one end at a point opposite the included'90 angle in a plane that bisects the included angle, and said raised portion having an inclined anvil comprises an elongated first substantially rectangular working surface and an elongated second substantially rectangular working surface, said first andsaid second working surfaces being attached along one; elongated edge to include a substantially 90 angle, a raised portion of rectangular cross section positioned on said tooladjacent one end; at a point opposite the included 90 angle in a plane that bisects the included angle, said raised portion terminating in an anvil surface to receive a blow for crimping a corner of a; duct, which anvil surface is inclined at an angle with the edge along which said first and second working surfaces are attached, and a handle at the opposite end of said tool from said raised portion to position the tool relative to a corner to be crimped.

Centeno Apr. 17, 1928 Gullholm July 17, 1956 

